Classical molecular dynamics study of small samples of amorphous silica : structural and dynamical properties

Abstract Ten small size samples of amorphous silica containing 78 atoms have been prepared using classical molecular dynamics and the van Beest-Kramer-van Santen (BKS) empirical potential. Our final goal is to use such samples in a forthcoming publication to compute accurately the thermal properties of silica from first principles calculations. The structural characteristics of these ten samples are in good agreement with experimental data. Dynamical properties, like the mean-square displacement, the vibrational density of states or the dynamic structure factor, have also been investigated and compare relatively well with data from neutron scattering experiments. These small dynamically stable structures can therefore be used subsequently to study more complicated physical properties, like the thermal conductivity or the diffusivity at a reduced computational cost.